1. Field of the Invention
The present invention generally relates to an apparatus for reciprocally powering one or more working tools and, more particularly, is concerned with a surface abrader apparatus employing such mechanism for reciprocally powering multiple impact abrading heads.
2. Description of the Prior Art
In the construction industry it is frequently necessary to abrade or roughen surfaces of concrete and other hard materials in order to prepare or refurbish the surfaces for bonding with other materials that are later applied thereto. It would be desirable to have an apparatus available that could be used to accomplish this task at a reasonable cost.
However, heretofore surface abrader machines, such as floor scabbler machines, typically have been air driven and relatively expensive to run. Because these machines are air driven, they require that a separate air compressor be brought to the work site to supply the compressed air to operate the machine. For instance, a typical floor scabbler machine needs an 180 cubic feet or larger air compressor to run even a relatively small floor scabbler machine.
Consequently, a need still exists for an innovation which will provide a solution to the aforementioned problem in the prior art without introducing any new problems in place thereof.
The present invention provides an apparatus for reciprocally powering one or more working tools to perform a variety of impact functions in a cost-effective manner and so satisfy the aforementioned need.
Accordingly, the present invention is directed to an apparatus which comprising: (a) a casing; (b) a motor mounted on the casing; (c) one or more working tools; and (d) an operating mechanism mounted to the casing and supporting the working tools outside of the casing. The operating mechanism is drivingly coupled to the motor for causing an impacting movement of the working tool against a surface in response to selected operation by the motor. The operating mechanism includes one or more elongated shafts reciprocally mounted in the casing parallel to one another and having same one lower ends extending from the casing, an input drive shaft rotatably mounted in the casing between and parallel to the shafts and rotatably driven by the motor, and means for lifting and releasing the shafts and the working tools mounted on the same one ends of the shafts to produce impact movements of the tools.
The means for lifting and releasing the shafts to reciprocally drive them along parallel axes includes a plurality of cam follower flanges each attached about one of the shafts and a plurality of coil springs each surrounding an upper end of one of the shafts opposite the lower end thereof supporting the working tool. The coil springs being upwardly yieldable are adapted to impose downwardly directed biasing forces on the cam follower flanges. The cam follower flanges and thus their shafts are sequentially lifted against the biasing forces of the coil springs and then abruptly released due to their engagement with an annular surface of a predetermined contour on an annular drive cam of the input drive shaft rotatably coupled to and driven by a rotary output shaft of the motor. Upon being abruptly released the shafts are driven downwardly along their parallel axes due to the biasing forces imposed on the flanges by the coil springs so as to cause forceable impact of their working tools with the surface. The shafts also are rotatably mounted such that the contacting of the annular drive cam on the rotating input drive shaft with the cam follower flanges on the shafts turns the shafts and the working tools therewith such that different areas of the surface are impacted by the tools.
In a preferred form, the apparatus is a surface abrader and the working tools are impact abrading heads adapted to forceably impact and abrade or roughen a surface, such as, of concrete or other relatively hard material.
These and other features and advantages of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings wherein there is shown and described an illustrative embodiment of the invention.